Seijuurou showing just why he's the captain of an elite swim team by setting a tournament record in his first swimming appearance.
Haru and Rin's race at the tournament is pretty intense. Even if you think Rin's a huge asshat for his comments afterward, his win is impressive.
Rei setting a personal best in his Butterfly heat despite his goggles slipping. He doesn't win, but the Determinator factor is great.
The Iwatobi team winning the relay at the tournament, despite only being told that Gou secretly signed them up the day right before and having very little time to prepare.
Rei finally demanding to know what happened between Haruka, Makoto, Nagisa, and Rin in episode 10. And then going to call Rin out on the whole thing at the end of the episode. Episode 11 is going to be a crowning episode of awesome for Rei, it looks like.
Episode 11 did turn out to be a Crowning Episode Of Awesome for Rei.
Episode Two. Rei swims the butterfly leg in a relay against Rin. It's informal, but they all make very clear they're there to win. And Rei wins. Not only his performance against Rin itself is awesome, but it shows how serious he has begun to take swimming and the club. (The whole race, really)